Preloaded Cartridge Prototype

[Davidvaini]

hey guys, I just finished my burst disk cartridge design yesterday and I thought i would post some pictures today. You may remember JSR trying to come up with a burst disk cartridge design a while back. Well my design is similar in which it uses a burst disk however the design is slightly different.

There is nothing wrong with JSR's cartridge design, however I wanted to make something that was simpler and easier to make. I wanted it to be easier to make because I plan on making a large amount of these and using them for airsoft.

My first prototype that I built today was made out of the following parts:

1. Tire Valve (shreader valve)
2. 3/4" SCH 40 PVC Cap
3. 3/4" SCH 40 PVC Coupling
4. 3/4" SCH 40 PVC Pipe.
5. Aluminum Foil Tape (Burst disk material)
6. kleenex paper tissues (wadding)
7. Airsoft BBs ( ammunition )

So those are the parts used for the cartridge, as for the firing tube that I insert the cartridges into.. it was simply a 1.25" PVC tube.

The design is simple but the results are amazing. The overall length of the prototype is 6 inches. When fired it will shoot BB's over a hundred feet easy. With a dry fire it sounds like a 12 gauge, when loaded with the bbs and wadding it sounds more like a real grenade launcher with that familiar bloop noise.

I then proceeded to make a larger cartridge. This time I used a 1" long design. It is about 2 feet long and is LOUD!! It sent BBs flying up and into the trees down the driveway and across the street. (driveway to street is 100 feet.)

Since the prototype works amazingly well, I plan on having the following:

1. Single Grenade Launcher with preloaded cartridges - Done
2. Three Barrel Grenade Launcher with G36 stock with preloaded cartridges - Done
3. Mortar with preloaded cartridges. - Still working on it.

VIDEO OF 1.25" Cartridge Firing!!!

[youtube][/youtube]

[Pyro Ninja]

Sounds great , what pressure are you running them and how are they triggered
Be sure to post images as soon as you get your camera up and working.

[starman]

Ahh yes, the joys of burst disk performance! I'm curious to see pics of your cartridge design. I have become quite a burst disk aficionado, albeit more in the combustion world. I would however like to see what you've got going there.

[Davidvaini]

running at different pressures. when hooked up to the compressor the compressor was outputting 100 PSI down to 60psi. I am going to be using one of those co2 duster things with 12gram cartridges to load/fire the burst disk cartridges.

[TwitchTheAussie]

Looks sexy.

[jackssmirkingrevenge]

How do you attach the disk, and how is it burst? I'm not seeing any form of mechanism.

[Pyro Ninja]

Sounds like he's just going to use air pressure from the co2 duster to "burst" the burst disk.

[Davidvaini]

pyro is correct. I actually have two different types... one where the burst disk holds the air untill it is punctured and one that is loaded and fired extremely quickly with the co2 duster (ssBOOM).

The burst disk is pinched between a coupling and a piece of pipe.

so you have the cap with the tire valve conected to a pipe. You attach the burst disk to the end of the pipe. You slide and push the coupling down tight. You are finished designing a dry fire cartridge.

If you want a loaded cartridge, you have the cap with the tire valve connected to a pipe. You take your wadding (rolled up toilet paper or Kleenex) and insert half way down your pipe. You then proceed to insert your BBs untill you reach the top of your pipe. You then attach your burst disk and slide your coupling over and you are finished.

If you want to pre-load it with air then you just attach a coupling with the trigger that pierces the disk rather than the plain coupling.

Its that simple.


Try one out, it takes like 5 min to make.

[Lentamentalisk]

well the triggered bursting is the hard part that JSR could never get to work all that successfully (or did he?)

I do like the simplicity of this though. Major props on simplicity!

[Davidvaini]

well the triggered bursting is the hard part that JSR could never get to work all that successfully (or did he?)

idk if he did but I did. And its really simple too..its just a small bolt that slides back and pierces the disk.

[Davidvaini]

Here is a new video:

[youtube][/youtube]

[Lentamentalisk]

I got to say, that does work nicely, though you are pretty much limited to 1 layer of foil arn't you? You could give each one its own union, but that is getting up there in price, for a single cartridge, and is on the bulky side.

[Imortal87]

I got to say, that does work nicely, though you are pretty much limited to 1 layer of foil arn't you? You could give each one its own union, but that is getting up there in price, for a single cartridge, and is on the bulky side.

actually, no, using foil tape you should be able to just stick on another layer

[Davidvaini]

NEW FIRING VIDEO!
[youtube][/youtube]

New pics:




Firing this heavy ceramic ball it went further than I expected. The ball was just sitting at the edge of the coupling and didn't really have any barrel. I was firing Nerf Foam Balls before this and trying to get it recorded but the foam balls shot so far and so fast that the camera couldnt pick it up.

So it will work awesome for airsoft as a grenade launcher.

Also another update, I decided to add wood furniture in between the g36 stock and the barrels. I stained the wood (pine) with red oak stain and the color looks like the wood from a AK47. I just have to attach the barrels and front grip and a quick coat of paint and it will be finished.

[Davidvaini]

note: im going to work on the gun today and there might be a chance I finish it.